2018 ... Mohammed A. Morovat [and seven others] · High mast illumination poles (HMIPs) are used throughout Texas and the U.S. to provide lighting along highways and at interchanges. Texas currently has about 5000 HMIPs, varying in height from 100 to 175 ft. Failures of HMIPs have been reported in several states, attributed to failures at

2018 ... Research Performed by: Center for Transportation Research; Research Supervisor: Michael D. Engelhardt; Researchers: Mohammed A. Morovat [and six others] · "Texas currently has about 5,000 [high mast illumination poles (HMIPs)], varying in height from 100 to 175 ft. Failures of HMIPs have been reported in several

2017 ... Colter Roskos [and seven others] · A number of full-scale tests have been carried out in the laboratory focused on the shear performance of simulated precast concrete deck panels (PCP). Shear tests were carried out to simulate the type of loading that will be applied to the deck panels as they are engaged as a bracing element. As

2017 ... Research Performed by Center for Transportation Research; Research Supervisor Michael D. Engelhardt; Researchers Kerry Kreitman [and three others] · "Many older bridges in the state of Texas were constructed with floor systems consisting of a non-composite concrete deck over steel girders. While the individual elements in these

2017 ... Kerry L. Kreitman [and four others] · In Implementation Project 5-6719, a non-composite continuous steel girder bridge located in Lakeport, Texas will be strengthened using techniques developed in TxDOT Research Project 0-6719. This strengthening technique involves the use of post-installed shear connectors in positive moment

[2016] ... Research Performed by: Center for Transportation Research; Research Supervisor: Todd Helwig; Researchers: Anthony Battistini [and four others] · "Currently, the Texas Department of Transportation (TxDOT) relies upon the use of standard details for cross frames in steel I-girder bridges—most frequently, the X-type and K-

2016 ... Research Performed by: Center for Transportation Research; Research Supervisor: Todd Helwig; Researchers: Konstantinos Belivanis [and five others] · "Elastomeric bearing pads have been utilized for support of bridge superstructures for several decades; however, the majority of these applications have typically consisted

2016 ... Research Performed by: Center for Transportation Research; Research Supervisor: Michael D. Engelhardt; Researchers: Kerry Kreitman [and five others] · "A number of older bridges in Texas were constructed with floor systems consisting of a non-composite concrete slab over steel girders. Many of these

2016 ... Konstantinos Victor Belivanis [and six others] · Elastomeric bearings have historically been used on bridges with short to moderate spans. The resulting demand on the bearings is usually not very severe in terms of the necessary support reaction or the deformational requirements. The bearings have historically showed good

2016 ... Kerry Kreitman [and six others] · This study investigated the use of post-installed shear connectors for strengthening existing non-composite continuous steel girder bridges. The existing bridges considered in this study have strength deficiencies in both the positive and the negative moment regions. The type of post-installed shear

2014 ... Hossein Yousefpour, Todd Helwig, Oguzhan Bayrak · This report provides an overview of a monitoring study on the West 7th Street Bridge in Ft Worth, Texas, that was carried out by The University of Texas at Austin (UT). The West 7th Street Bridge was designed by the Texas Department of Transportation (TxDOT) and is believed

2014 ... Anthony Battistini [and five others] · Cross frames are critical members for the stability of straight and curved steel bridges. Conventional cross frames are often fabricated from steel angles; however these members have relatively poor structural behavior. Because of the low buckling strength, cross frames with angle diagonals

2012 ... [Todd Helwig, University of Texas at Austin] · This software product was developed and is maintained by the University of Texas at Austin. UTCGAT is a suite of software tools for the analysis of curved girders. The suite consists of UT Bridge and UT Lift. UT Bridge is a 3-dimensional finite element program for the analysis of curved

2011 ... RS: Michael Engelhardt; Researchers: Anthony Battistini [and five others] · The primary objective of this project was to develop an improved detail for attaching skewed cross-frames to girders that provides higher stiffness and better structural performance than the conventional bent plate detail. A secondary objective of this

2010 ... Craig Quadrato [and six others] · This report documents a research investigation on connection details and bracing layouts for stability bracing of steel bridges with skewed supports. Cross-frames and diaphragms play an important role in stabilizing steel girders, particularly during construction. The commonly used bent plate

2010 ... Jason Stith [and six others] · Project 0-5574 "Curved Plate Girder Design for Safe and Economical Construction," resulted in the development of two design tools, UT Lift and UT Bridge. UT Lift is a spreadsheet-based program for analyzing steel girders during lifting while UT Bridge is a three-dimensional finite element

2010 ... by Jason Stith [and four others] · The purpose of this spreadsheet is to provide a tool and give information to an engineer when deciding the safety of lifting a horizontally curved steel I-girder with one crane and two lift clamps. The spreadsheet has been developed to indicate the necessary inputs and highlight the calculated

2010 ... Jason Stith [and eight others] · This report summarizes the methods, results, and recommendations from a research investigation on the behavior of horizontally curved girders during construction. The primary focus of this study is the behavior during early stages of construction when little or no bracing is provided. Girder

2010 ... Seongyeong Yang [and four others] · Economical constraints on the design of bridges usually necessitate the use of as few girders as possible across the bridge width. The girders are typically uniformly spaced transversely with the deck extending past the fascia girders, thereby resulting in an overhang. While designers

2010 ... Jason Stith [and five others] · The purpose of this set of guidelines is to summarize recommendations from work completed as part of the Texas Department of Transportation (TxDOT) Research Project 0-5574 entitled "Curved Plate Girder Design for Safe and Economic Construction." The research included field tests, three-

2009 ... Todd Helwig [and four others] · Economical constraints on the design of bridges usually necessitate the use of as few girders as possible across the bridge width. The girders are typically uniformly spaced transversely with the deck extending past the fascia girders, thereby resulting in an overhang. While designers commonly

2009 ... Todd Helwig [and eight others] · Horizontally curved steel I-girder bridges are important components of the highway system that are commonly used for providing efficient transfer of traffic between major thoroughfares. The critical stage for the stability of these curved bridges generally occurs during early stages of erection and

2007 ... Todd Helwig [and four others] · The frequency of use of steel box girders has increased in the state of Texas and throughout the United States over the past 10 years. Some of the advantages of the structural shape that have led to the increased utilization include improved aesthetic, maintenance, and structural benefits.

2007 ... Todd Helwig, Eric Williamson and Reagan Herman · Since 1995, the Texas Department of Transportation (TxDOT) has funded several studies on trapezoidal box girders. The research in these studies was some of the first detailed work on curved box girders that had been carried out in nearly twenty years. Although the studies

2006 ... Reagan S. Herman, Todd A. Helwig and Dawei Li · The purpose of this investigation was to improve understanding of trapezoidal box girder systems with skewed supports. The impact of external K-frames on the behavior of the internal K-frames and top lateral truss was also studied. The research investigation included both

2005 ... Todd A. Helwig [and three others] · Lateral torsion buckling is a failure mode that is generally critical during the construction stages for steel bridges. Prior to curing of concrete deck, the steel girders must support the entire load. The buckling capacity of the girders is improved by providing cross-frames and diaphragms at

2005 ... Todd A. Helwig, O. Ozgur Egilmez and Charles A. Jetann · Lateral torsional buckling is a failure mode that often controls the design of steel bridge girders during construction. Bracing in the form of cross-frames and diaphragms is often provided at locations along the bridge length to reduce the unbraced length and increase the

2005 ... by Todd Helwig, Ozgur Egilmez, and Charles Jetann · Traditional bracing systems for steel bridge girders typically consist of cross frames and diaphragms spaced along the length of the bridge. Other sources of bracing may provide improved performance and economy. Permanent metal deck forms are often used as formwork for

2004 ... by Todd A. Helwig, Reagan S. Herman, and Dawei Li · Trapezoidal steel box girder systems are frequently used in Texas for the construction of highway interchanges and elevated expressways in urban areas. There are a number of aspects of box girder bridges, including both aesthetic and structural advantages, which

2003 ... Todd Helwig and Liqun Wang · Steel bridge girders are prone to buckling from construction loads during casting of the concrete for the composite deck. The buckling capacity of the steel girders can be increased by providing bracing at intermediate locations along the girder length. The intermediate bracing typically takes the

2000 ... by Todd Helwig and Zhanfei Fen · Trapezoidal steel box girders are seeing increased use in the state of Texas as well as throughout the United States. In addition to a number of serviceability and aesthetic advantages for trapezoidal box girders, the large torsional stiffness of the closed box section is also a major structural